1. Field of the Invention
The structure of this invention is an alignment guide and more particularly relates to an alignment guide for use in an MK-19 grenade launcher for positioning rounds in the receiver assembly for the delinking and pickup thereof by the bolt extractors of such weapon.
2. Description of the Prior Art
At the front of the receiver assembly of an MK-19 grenade launchers is an alignment guide which has a slot defined therein that receives the ogive portion of each of the rounds as they are entered into the weapon, such rounds being linked to one another. The rounds are advanced with their ogive portions riding in the slot and with the lengths of their bodies perpendicular to the alignment guide. When each round reaches the position for its delinking, it is positioned in front of a bowl-shaped aperture in the alignment guide, hereinafter referred to as the "bowl." The round is advanced into the bowl and then retracted, causing the round to be delinked from the next adjacent round. The round is retained at its rear rim by the bolt extractors. The edge of the bowl of the alignment guide is sharp due to the fact that the increasing width of the bowl at its top nearly coincides with the outside width of the alignment guide, resulting in an area of stress concentration. After the round is pulled rearward by the bolt extractors, it is moved to its firing position. At the top and bottom of the alignment guide are rail members. A center hole is provided for a spring attachment screw. First and second body apertures are provided on each side of the member containing the center hole. The body of the prior art alignment guide is thickened in most of the area around the bowl which configuration causes the edge of the bowl to contact the ogive of the round. The features of the edge rails, thickened body around the bowl and body apertures are initially cast into the structure of the prior art alignment guide. Because of the thickness and resulting weight of the body of the prior art alignment guide, a pair of elongated slots are cut in the rear of the prior art alignment guide to diminish the weight of the structure. All of the above-mentioned features of the prior art alignment guide necessitate a great deal of machining to be performed on the casting to manufacture such prior art alignment guide.